TY - JOUR

T1 - High-pressure Raman study of Na-Ca burbankite—A possible CO2 host in deep mantle

AU - Rashchenko, Sergey

AU - Mikhno, Anastasia

AU - Shatskiy, Anton

N1 - Funding Information: We thank reviewer Junji Yamamoto and anonymous reviewers for their constructive comments that helped improve the manuscript. We thank Dr. Philippe Colomban for the editorial handling. The research was supported by a Russian Science Foundation grant (№ 21‐77‐00016). The authors acknowledge Anastasia Brazhnikova and Konstantin Glazyrin for their participation in data collection. Publisher Copyright: © 2022 John Wiley & Sons Ltd.

PY - 2023/1/1

Y1 - 2023/1/1

N2 - Na-Ca carbonates synthesized in high-pressure experiments and found in mineral inclusions inside diamonds, exhumed from mantle depths, attract a lot of attention as potential hosts of subducted CO2 in the deep mantle and sources of carbonate-rich magmas, involved in mantle metasomatism and diamond formation. However, the Na-Ca carbonates synthesized at pressures of mantle transition zone (13–24 GPa) were not characterized structurally or spectroscopically. At the same time, the stability of well-characterized Na-Ca carbonates synthesized at lower pressures (3–6 GPa) at higher pressures was never studied in in situ experiments. Here, we report an in situ Raman study of Na-Ca burbankite, Na2Ca4(CO3)5, synthesized at 6 GPa using diamond anvil cell technique up to the pressures of 24 GPa, corresponding to the mantle transition zone. The obtained results link the observations from experiments corresponding both to the upper mantle and mantle transition zone by demonstration of structural stability of Na-Ca burbankite and the absence of phase transitions up to 24 GPa (at least at ambient temperature). The latter allows to preliminary assign the Na-Ca-carbonates synthesized in carbonated pelites and eclogites under pressures of mantle transition zone to the burbankite structural type.

AB - Na-Ca carbonates synthesized in high-pressure experiments and found in mineral inclusions inside diamonds, exhumed from mantle depths, attract a lot of attention as potential hosts of subducted CO2 in the deep mantle and sources of carbonate-rich magmas, involved in mantle metasomatism and diamond formation. However, the Na-Ca carbonates synthesized at pressures of mantle transition zone (13–24 GPa) were not characterized structurally or spectroscopically. At the same time, the stability of well-characterized Na-Ca carbonates synthesized at lower pressures (3–6 GPa) at higher pressures was never studied in in situ experiments. Here, we report an in situ Raman study of Na-Ca burbankite, Na2Ca4(CO3)5, synthesized at 6 GPa using diamond anvil cell technique up to the pressures of 24 GPa, corresponding to the mantle transition zone. The obtained results link the observations from experiments corresponding both to the upper mantle and mantle transition zone by demonstration of structural stability of Na-Ca burbankite and the absence of phase transitions up to 24 GPa (at least at ambient temperature). The latter allows to preliminary assign the Na-Ca-carbonates synthesized in carbonated pelites and eclogites under pressures of mantle transition zone to the burbankite structural type.

KW - burbankite

KW - carbonate

KW - deep carbon cycle

KW - diamond anvil cell

KW - high pressure

UR - http://www.scopus.com/inward/record.url?scp=85140395370&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/d6d4e8ca-104c-329d-a9ae-0312b0be589d/

U2 - 10.1002/jrs.6463

DO - 10.1002/jrs.6463

M3 - Article

AN - SCOPUS:85140395370

VL - 54

SP - 101

EP - 106

JO - Journal of Raman Spectroscopy

JF - Journal of Raman Spectroscopy

SN - 0377-0486

IS - 1

ER -